在外部点击iOS 8上关闭模式表单表视图

Question

I've been trying to dismiss the modal form sheet view on outside tap on iOS 8 with no luck, I've tried this code

UITapGestureRecognizer *recognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapBehind:)];

[recognizer setNumberOfTapsRequired:1];
recognizer.cancelsTouchesInView = NO; //So the user can still interact with controls in the modal view
[self.view.window addGestureRecognizer:recognizer];

- (void)handleTapBehind:(UITapGestureRecognizer *)sender
{

if (sender.state == UIGestureRecognizerStateEnded)
 {
   CGPoint location = [sender locationInView:nil]; //Passing nil gives us coordinates in the window

 //Then we convert the tap's location into the local view's coordinate system, and test to see if it's in or outside. If outside, dismiss the view.

    if (![self.view pointInside:[self.view convertPoint:location fromView:self.view.window] withEvent:nil]) 
    {
       // Remove the recognizer first so it's view.window is valid.
      [self.view.window removeGestureRecognizer:sender];
      [self dismissModalViewControllerAnimated:YES];
    }
 }
}

But it doesn't detect outside view clicks, any suggestions ?

Answer 1

There are actually two problems in iOS 8. First, the gesture recognition does not begin.

I solved this by adding the UIGestureRecognizerDelegate protocol and implementing

-(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer*)otherGestureRecognizer
{
    return YES;
}

Also, don't forget to register the delegate with

recognizer.delegate = self;

Now the gesture recognizer should recognize gestures and the target method ( handleTapBehind: ) will be called.

Here comes the second problem in iOS 8: locationInView: doesn't seem to take the device orientation into account if nil is passed as a view. Instead, passing the root view works.

Here's my target code that seems to work for iOS 7.1 and 8.0:

if (sender.state == UIGestureRecognizerStateEnded) {
    UIView *rootView = self.view.window.rootViewController.view;
    CGPoint location = [sender locationInView:rootView];
    if (![self.view pointInside:[self.view convertPoint:location fromView:rootView] withEvent:nil]) {
        [self dismissViewControllerAnimated:YES completion:^{
            [self.view.window removeGestureRecognizer:sender];
        }];
    }
}

Answer 2

In iOS 8, You can look at using the new UIPresentationController class. It gives you better control over the container around your custom view controller presentation (allowing you to correctly add a gesture recogniser of your own).

Here is a link to quite a simple tutorial as well: http://dativestudios.com/blog/2014/06/29/presentation-controllers/

Then add the dimming view tap-to-dismiss:

    UITapGestureRecognizer *singleFingerTap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleSingleTap:)];
    [self.dimmingView addGestureRecognizer:singleFingerTap];


- (void)handleSingleTap:(UITapGestureRecognizer *)recognizer {
    [self.presentingViewController dismissViewControllerAnimated:YES completion:nil];
}

Answer 3

Swift 3.1 solution that works in both portrait and landscape.

class TapBehindModalViewController: UIViewController, UIGestureRecognizerDelegate {
    private var tapOutsideRecognizer: UITapGestureRecognizer!

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)

        if(self.tapOutsideRecognizer == nil) {
            self.tapOutsideRecognizer = UITapGestureRecognizer(target: self, action: #selector(self.handleTapBehind))
            self.tapOutsideRecognizer.numberOfTapsRequired = 1
            self.tapOutsideRecognizer.cancelsTouchesInView = false
            self.tapOutsideRecognizer.delegate = self
            self.view.window?.addGestureRecognizer(self.tapOutsideRecognizer)
        }
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)

        if(self.tapOutsideRecognizer != nil) {
            self.view.window?.removeGestureRecognizer(self.tapOutsideRecognizer)
            self.tapOutsideRecognizer = nil
        }
    }

    func close(sender: AnyObject) {
        self.dismiss(animated: true, completion: nil)
    }

    // MARK: - Gesture methods to dismiss this with tap outside
    func handleTapBehind(sender: UITapGestureRecognizer) {
        if (sender.state == UIGestureRecognizerState.ended) {
            let location: CGPoint = sender.location(in: self.view)

            if (!self.view.point(inside: location, with: nil)) {
                self.view.window?.removeGestureRecognizer(sender)
                self.close(sender: sender)
            }
        }
    }

    func gestureRecognizer(_ gestureRecognizer: UIGestureRecognizer, shouldRecognizeSimultaneouslyWith otherGestureRecognizer: UIGestureRecognizer) -> Bool {
        return true
    }
}